Digital X-ray detector and method for manufacturing the X-ray detector

ABSTRACT

Provided herein is a digital x-ray detector wherein a plurality of sensing pixels are formed in a matrix structure, and wherein a pin structure positioned in an odd number line and a pin structure positioned in an even number line are not formed in the same process, thereby preventing a line detect by a particle.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2015-0014944 filed Jan. 30, 2015, the disclosure of which is herebyincorporated in its entirety by reference.

BACKGROUND

1. Field

The following description relates to a digital x-ray detector, and moreparticularly, to a digital x-ray detector capable of preventing linedefects in the digital x-ray detector, and a method for manufacturingthe same.

2. Description of Related Art

A digital x-ray detector is a device configured to convert x-ray thatpenetrated a human body into electrical signals, digitalize thoseelectrical signals and then detect those digitalized signals. Digitalx-ray detectors are used in medical inspection apparatuses, andnondestructive inspection apparatuses and the like. Digital x-raydetectors are largely classified into direct method detectors andindirect method detectors depending on the method of converting incidentx-ray into electrical signals.

The direct method is a method of using external power supply to collectelectrons and pairs of positive holes being generated in an x-rayreceptor layer constituting a digital x-ray detector as the x-ray thatpenetrated a human body enters the x-ray receptor layer.

The indirect method is a method of using the radiance phenomenon thatoccurs as the x-ray that penetrated a human body enters an x-rayreceptor layer made of a fluorescent material.

A conventional digital x-ray detector includes a plurality of lines.Each of these lines includes a plurality of sensing pixels. In aconventional digital x-ray detector, when a certain line of theplurality of lines is short-circuited with an adjacent line, all thepixels inside the short-circuited lines will be disabled, causing linedefects.

More specifically, explanation will be made on short circuits betweenlines in a conventional digital x-ray detector with reference to FIG. 1.FIG. 1 is an exemplary view of a conventional digital x-ray detector.Referring to FIG. 1A and FIG. 1B, after a process of manufacturing aconventional digital x-ray detector 100 is completed with a particle 120positioned between the lines, and power is applied to test the product,a short circuit may occur due to the particle 120 between the lines,causing a line defect. In a process of manufacturing a conventionaldigital x-ray detector 100 with a particle positioned between the lines,a conduction may occur between an upper electrode 111-1 of a sensingpixel of an odd number line 110-1 and an upper electrode 111-2 of asensing pixel formed on an even number line 110-2 adjacent to the oddnumber line 110-1 through a particle 120, thereby causing a shortcircuit. In this case, line defects may occur in the same odd and evennumber lines 110-1, 110-2 that include the short-circuited upperelectrode. These odd and even number lines 110-1, 110-2 where linedefects occurred are not capable of performing functions of convertingx-ray into electrical signals.

Thus, there has been a need to develop a digital x-ray detector capableof preventing line defects and a manufacturing method thereof.

SUMMARY

A purpose of the present disclosure is to resolve the aforementionedproblems of prior art, that is, to provide a digital x-ray detectorcapable of preventing lines defects, and a manufacturing method thereof.

According to an embodiment of the present disclosure, there is provideda method for manufacturing a digital x-ray detector wherein a pluralityof units of sensing pixels are formed in a matrix structure, the methodincluding forming a thin film transistor on every unit of sensing pixelarea on an upper portion of a substrate; forming a first pin structureon each source electrode of a thin film transistor positioned in an oddnumber line; forming a first protective layer that covers an upperportion of the substrate where the first pin structures are formed;forming, on the first protective layer, a first data hole line thatexposes a drain electrode of a thin film transistor positioned in thesame odd number line in a row, a first bias hole line that exposes anupper electrode of the first pin structure positioned in the same oddnumber line in a row, a second data hole line that exposes a drainelectrode of a thin film transistor positioned in the same even numberline in a row, and a second pin structure hole that exposes a sourceelectrode of a thin film transistor positioned in an even number line;forming a first data wire inside the first data hole line, and forming afirst bias wire inside the first bias hole line; forming a second pinstructure to be electrically connected to a source electrode of eachthin film transistor exposed inside the second pint structure hole;forming a second protective layer that covers an upper portion of asubstrate where the first data wire, first bias wire and second pinstructure are formed; forming, on the second protective layer, a seconddata hole line that exposes a drain electrode of a thin film transistorpositioned in the same even number line in a row and a second bias holeline that exposes an upper electrode of the second pin structurepositioned in the same line in a row; and forming a second data wireinside the second data hole line and forming a second bias wire insidethe second bias hole line.

The method may further include forming a light shield film that shieldsan upper portion of an active layer of the thin film transistor on anupper portion of the second protective layer, after the forming of asecond protective layer.

The light shield film may be formed in the shape of a plurality of linesthat shield the upper portion of the active layer of each thin filmtransistor positioned in the same odd number line and same even numberline in a row.

The light shield film may be formed at the same step with the seconddata wire and second bias wire.

The method may further include forming a third protective layer thatcovers an upper portion of a substrate where the second data wire andfirst bias wire are formed.

According to another embodiment of the present disclosure, there isprovided a digital x-ray detector where a plurality of units of sensingpixels are formed in a matrix structure, the detector including a thinfilm transistor formed on every unit of sensing pixel area on an upperportion of a substrate; a first pin structure formed on each sourceelectrode of a thin film transistor positioned in an odd number line; asecond pin structure formed on each source electrode of a thin filmtransistor positioned in an even number line; a first data wire thatconnects a drain electrode of a thin film transistor positioned in thesame odd number line in a row; a second data wire that connects a drainelectrode of a thin film transistor positioned in the same even numberline in a row; a first bias wire that connects an upper electrode of thefirst pin structure positioned in the same odd number line in a row; asecond bias wire that connects an upper electrode of the second pinstructure positioned in the same even number line in a row; and a firstprotective layer that covers an upper portion of the substrate where thethin film transistor and first pin structure are formed, wherein thesecond pin structure is formed inside a hole formed in the firstprotective layer.

The first data wire and first bias wire may be formed inside a hole lineformed in the first protective layer.

The digital x-ray detector may further include a second protective layerformed on an upper portion of the first protective layer, wherein thesecond data wire is formed inside a hole line formed to penetrate thefirst protective layer and second protective layer, and the second biaswire is formed inside a hole line formed in the second protective layer.

The digital x-ray detector may further include, on an upper portion ofthe second protective layer, a light shield film that shields an upperportion of the active layer of the thin film transistor.

The light shield film may be formed in the shape of a plurality of linesthat shield the upper portion of the active layer of the thin filmtransistor positioned in the same odd number line and the same evennumber line in a row.

The digital x-ray detector may further include a third protective layerformed on an upper portion of the second protective layer.

According to the aforementioned various embodiments of the presentdisclosure, it is possible to prevent line defects between a certainline and its adjacent line of a digital x-ray detector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are an exemplary views of a conventional digital x-raydetector;

FIGS. 2A-2J are cross-section views illustrating a method formanufacturing a digital x-ray detector according to an embodiment of thepresent disclosure; and

FIG. 3 is an exemplary plan view of a digital x-ray detector accordingto an embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will beexplained in detail with reference to the illustrations in the drawingsattached hereto. However, the present disclosure is not limited by theexemplary embodiments. The like reference numerals indicate the likecomponents throughout the drawings attached.

Terms including ordinal numbers such as “first”, “second” and the likemay be used to explain various components, but the components are notlimited by those terms. These terms are only intended to differentiateone component from other components. For example, a first component maybe referred to as a second component without departing from the scope ofright of the present disclosure. Likewise, a second component may bereferred to as a first component. The terms used in the presentapplication are only intended to explain a certain embodiment, and notto limit the present disclosure. Furthermore, the terms used in asingular form may include a plural form unless clearly meaning otherwisein the context.

Furthermore, throughout the present specification, “include/comprise” or“including/comprising” means that components may be further addedwithout excluding the possibility of existence of other components.

A digital x-ray detector according to embodiments of the presentdisclosure includes a plurality of sensing pixels formed in a matrixstructure. Each sensing pixel includes each one of a thin filmtransistor, lower electrode, pin structure, and upper electrode. Theplurality of sensing pixels may be divided into odd number lines andeven number lines.

Hereinafter, a digital x-ray detector and a manufacturing method thereofaccording to an embodiment of the present disclosure will be explainedwith reference to FIGS. 2A-2J and 3.

FIGS. 2A-2J are cross-section views illustrating a method formanufacturing a digital x-ray detector according to an embodiment of thepresent disclosure. Referring to FIG. 2A, first of all, there may beperformed a step of forming a thin film transistor 230-1, 230-2 on everyunit sensing pixel area on an upper portion of a substrate 220 of an oddnumber line 210-1 and even number line 210-2 of the digital x-raydetector 200 according to the embodiment of the present disclosure.

More specifically, on an upper portion of the substrate 220, on everyunit sensing pixel area that is where a unit sensing pixel will beformed, a first and second thin film transistor 230-1, 230-2 thatinclude a first and second gate electrode 231-1, 231-2, a first andsecond drain electrode 233-1, 233-2, a first and second source electrode234-1, 234-2, and a first and second active layer 232-1, 232-2. Herein,a portion of the first and second source electrode 234-1, 234-2 may eachbe used as a lower electrode of a first pin structure 240-1 and a lowerelectrode of a second pin structure 240-2, respectively, that will beexplained hereinafter.

Thereafter, referring to FIG. 2B, there may be performed a step offorming the first pin structure 240-1 on each source electrode 234-1 ofthe thin film transistor 230-1 positioned in the odd number line 210-1.

More specifically, the first pin structure 240-1 includes a first N typesemiconductor pattern 241-1 formed on a portion of the first sourceelectrode 234-1 being used as a lower electrode (not illustrated), afirst intrinsic semiconductor pattern 242-1 formed on the first N typesemiconductor pattern 241-1, a first P type semiconductor pattern 243-1formed on the first intrinsic semiconductor pattern 242-1, and a firstupper electrode 244-1 formed on the first P type semiconductor pattern243-1. Herein, the first N type semiconductor pattern 241-1 may be madeof N+ a-Si, the first intrinsic semiconductor pattern 242-1 may be madeof a-Si, and the first P type semiconductor pattern 243-1 may be made ofP+ a-Si. Furthermore, the first upper electrode 244-1 may be made of atransparent electrode material.

Thereafter, referring to FIG. 2C, there may be performed a step offorming a first protective layer 250-1 that covers an upper portion ofthe substrate 220 where the first pin structures 240-1 are formed.

More specifically, it is possible to form the first protective layer250-1 (ILD: Inter-layer Dielectric) that covers the upper portion of thesubstrate 220 of the odd number line 210-1 and even number line 210-2 ofthe digital x-ray detector 200 where the first pin structures 240-1 areformed. Herein, the first protective layer 250-1, and a secondprotective layer 250-2 and third protective layer 250-3 that will beexplained hereinafter may be made of any one of SiO₂, SiNs and SiOn.

Thereafter, referring to FIG. 2D, there may be performed a step offorming, on the first protective layer 250-1, a first data hole line261-1 for exposing the drain electrode 233-1 of the thin film transistor230-1 positioned in the same odd number line 210-1 in a row, a firstbias hole line 263-1 for exposing the upper electrode 244-1 of the firstpin structure 240-1 positioned in the same odd number line 210-1 in arow, a second data hole line 261-2 for exposing the drain electrode233-2 of the thin film transistor 230-2 positioned in the same evennumber line 210-2 in a row, and a second pin structure hole 262 forexposing the source electrode 234-2 of the thin film transistor 230-2positioned in the same even number line 210-2 in a row.

More specifically, the first data hole line 261-1, first bias hole line263-1, second data hole line 261-2, and second pin structure hole 262may be created through an etching process after performing a process ofexposing the first protective layer 250-1 to light.

Thereafter, referring to FIG. 2E, there may be performed a step offorming a first data wire 271-1 in the first data hole line 261-1 andforming a first bias wire 272-1 in the first bias hole line 263-1.

More specifically, the first data wire 271-1 is electrically connectedto the drain electrode 233-1 of the thin film transistor 230-1positioned in the same odd number line 210-1, and the first bias wire272-1 is electrically connected to the upper electrode 244-1 of thefirst pin structure 240-1 positioned in the same odd number line 210-1.

Thereafter, referring to FIG. 2F, it is possible to form the second pinstructure 240-2 to be electrically connected to the source electrode234-2 of each thin film transistor 230-2 exposed in the second pinstructure hole 262.

More specifically, the second pin structure 240-2 includes a second Ntype semiconductor pattern 241-2 formed on a portion of the secondsource electrode 234-2 used as a lower electrode, a second intrinsicsemiconductor pattern 242-2 formed on the second N type semiconductorpattern 241-2, a second P type semiconductor pattern 243-2 formed on thesecond intrinsic semiconductor pattern 242-2, and a second upperelectrode 244-2 formed on the second P type semiconductor pattern 243-2.Herein, the second N type semiconductor pattern 241-2 may be made of N+a-Si, the second intrinsic semiconductor pattern 242-2 may be made ofa-Si, and the second P type semiconductor pattern 243-2 may be made ofP+a-Si. Furthermore, the second upper electrode 244-2 may be made of atransparent electrode material.

Thereafter, referring to FIG. 2G, there may be performed a step offorming a second protective layer 250-2 that covers an upper portion ofthe substrate 220 where the first data wire 271-1, first bias wire 272-1and second pin structure 240-2 are formed.

Thereafter, referring to FIG. 2H, there may be performed a step offorming, on the second protective layer 250-2, a second data hole line261-2 for exposing the drain electrode 233-2 of the thin film transistorpositioned in the same even number line 210-2 in a row, and a secondbias hole line 263-2 for exposing the upper electrode 244-2 of thesecond pin structure 240-2 positioned in the same even number line 210-2in a row.

More specifically, the second data hole line 261-2 and second bias holeline 263-2 may be formed through an etching process after performing aprocess of exposing the second protective layer 250-2 to light.

Thereafter, referring to FIG. 2I, there may be performed a step offorming a second data wire 271-2 on the second data hole line 261-2 andforming a second bias wire 272-2 on the second bias hole line 263-2.

More specifically, the second data wire 271-2 is electrically connectedto the drain electrode 233-2 of the thin film transistor 230-2positioned in the same even number line 210-2, and the second bias wire272-2 is electrically connected to the upper electrode 244-2 of thesecond pin structure 240-2 positioned in the same even number line210-2.

Furthermore, referring to FIG. 2I, there may be further performed a stepof forming, on an upper portion of the second protective layer 250-2, afirst and second light shield film 270-1, 270-2 for shielding upperportions 232-1, 232-2 of the active layers of the thin film transistors230-1, 230-2.

Furthermore, referring to FIG. 2J, there may be performed a step offorming a third protective layer 250-3 that covers an upper portion ofthe substrate where the second data wire 271-2 and second bias wire272-2 are formed.

Hereinafter, a digital x-ray detector according to an embodiment of thepresent disclosure will be explained in detail with reference to FIG. 3.

FIG. 3 is an exemplary plan view of a digital x-ray detector accordingto an embodiment of the present disclosure. Referring to FIG. 3, even ifa particle (not illustrated) exists between an odd number line and evennumber line after the first upper electrode 234-1 is formed on thesubstrate of the odd number line, a conduction does not occur betweenthe first upper electrode 234-1 and second upper electrode 234-2 by theparticle (not illustrated).

Meanwhile, as explained in detail with reference to FIGS. 2 to 3, in thedigital x-ray detector according to an embodiment of the presentdisclosure, even if there exists a particle (not illustrated) between anodd number line and even number line in a manufacturing process, by atleast one of the first protective layer 250-1 to the third protectivelayer 250-3, the first upper electrode 234-1 of the first pin structure240-1 formed in the same odd number line 210-1 and the second upperelectrode 234-2 of the second pin structure 240-2 formed in the sameeven number line 210-2 are not electrically connected to each otherthrough the particle (not illustrated).

Only certain characteristics of the present disclosure are illustratedand explained in the present specification, and various modificationsand changes can be made by one skilled in the art. Therefore, it will beunderstood that the claims are intended to include changes andmodifications within the spirit and scope of the present disclosure.

What is claimed is:
 1. A method for manufacturing a digital x-raydetector wherein a plurality of sensing pixels are formed in a matrixstructure, the method comprising: forming a thin film transistor onevery sensing pixel area on an upper portion of a substrate; forming afirst pin structure on each source electrode of the thin film transistorpositioned in an odd number line; forming a first protective layer thatcovers an upper portion of the substrate where the first pin structuresare formed; forming, on the first protective layer, a first data holeline that exposes a drain electrode of the thin film transistorpositioned in the same odd number line in a row, a first bias hole linethat exposes an upper electrode of the first pin structure positioned inthe same odd number line in a row, a second data hole line that exposesa drain electrode of another thin film transistor positioned in the sameeven number line in a row, and a second pin structure hole that exposesa source electrode the another thin film transistor positioned in aneven number line; forming a first data wire inside the first data holeline, and forming a first bias wire inside the first bias hole line;forming a second pin structure to be electrically connected to thesource electrode of each of the another thin film transistor exposedinside the second pin structure hole; forming a second protective layerthat covers the upper portion of the substrate where the first datawire, first bias wire and second pin structure are formed; forming, onthe second protective layer, the second data hole line that exposes thedrain electrode the another thin film transistor positioned in the sameeven number line in a row and a second bias hole line that exposes anupper electrode of the second pin structure positioned in the same linein a row; and forming a second data wire inside the second data holeline and forming a second bias wire inside the second bias hole line. 2.The method of claim 1, further comprising forming a light shield filmthat shields an upper portion of an active layer of the thin filmtransistor on an upper portion of the second protective layer, after theforming of the second protective layer.
 3. The method of claim 2,wherein the light shield film is formed in a shape of a plurality oflines that shield the upper portion of the active layer of each thinfilm transistor positioned in the same odd number line and same evennumber line in a row.
 4. The method of claim 3, wherein the light shieldfilm is formed at the same step with the second data and second biaswire.
 5. The method of claim 4, further comprising forming a thirdprotective layer that covers the upper portion of the substrate wherethe second data wire and first bias wire are formed.
 6. The method ofclaim 3, further comprising forming a third protective layer that coversthe upper portion of the substrate where the second data wire and firstbias wire are formed.
 7. The method of claim 2, wherein the light shieldfilm is formed at the same step with the second data wire and secondbias wire.
 8. The method of claim 7, further comprising forming a thirdprotective layer that covers the upper portion of the substrate wherethe second data wire and first bias wire are formed.
 9. The method ofclaim 2, further comprising forming a third protective layer that coversthe upper portion of the substrate where the second data wire and firstbias wire are formed.
 10. The method of claim 1, further comprisingforming a third protective layer that covers the upper portion of thesubstrate where the second data wire and first bias wire are formed. 11.A digital x-ray detector where a plurality of units of sensing pixelsare formed in a matrix structure, the detector comprising: a thin filmtransistor formed on every sensing pixel area on an upper portion of asubstrate; a first pin structure formed on each source electrode of thethin film transistor positioned in an odd number line; a second pinstructure formed on each source electrode of the another thin filmtransistor positioned in an even number line; a first data wire thatconnects a drain electrode of the thin film transistor positioned in thesame odd number line in a row; a second data wire that connects a drainelectrode the another thin film transistor positioned in the same evennumber line in a row; a first bias wire that connects an upper electrodeof the first pin structure positioned in the same odd number line in arow; a second bias wire that connects an upper electrode of the secondpin structure positioned in the same even number line in a row; and afirst protective layer that covers the upper portion of the substratewhere the thin film transistor and the first pin structure are formed,wherein the second pin structure is formed inside a hole formed in thefirst protective layer.
 12. The digital x-ray detector of claim 11,wherein the first data wire and the first bias wire are formed inside ahole line formed in the first protective layer.
 13. The digital x-raydetector of claim 11, further comprising a second protective layerformed on an upper portion of the first protective layer, wherein thesecond data wire is formed inside a hole line formed to penetrate thefirst protective layer and the second protective layer, and the secondbias wire is formed inside the hole line formed in the second protectivelayer.
 14. The digital x-ray detector of claim 13, wherein a lightshield film that shields an upper portion of an active layer of the thinfilm transistor is further formed on an upper portion of the secondprotective layer.
 15. The digital x-ray detector of claim 14, whereinthe light shield film is formed in a shape of a plurality of lines thatshield the upper portion of the active layer of the thin film transistorpositioned in the same odd number line and the same even number line ina row.
 16. The digital x-ray detector of claim 15, further comprising athird protective layer formed on the upper portion of the secondprotective layer.
 17. The digital x-ray detector of claim 14, furthercomprising a third protective layer formed on the upper portion of thesecond protective layer.
 18. The digital x-ray detector of claim 13,further comprising a third protective layer formed on an upper portionof the second protective layer.